The present invention relates to a drive unit for driving or braking a ring gear, comprising a motor or a brake, a transmission and an output shaft on which a pinion is arranged for driving the ring gear.
Such drive units are used for example for driving slewing or swing gears, in particular for driving a slewing gear of a wind turbine or for driving a slewing or swing gear of a crane or an excavator. The ring gear has teeth on its outer circumference or inner circumference, which mesh with the teeth of the pinion. By driving the pinion via the output shaft, the ring gear thus can be driven. Ring gears are also used for driving winches, in particular for driving winches of a crane.
For driving a ring gear, a plurality of drive units can also be used in parallel, when great drive forces are required.
For such drive units, overload protection devices, e.g. in the form of slip clutches or predetermined breaking points, are known already, which are arranged between the motor and the transmission. In this way, the torque flow running from the drive motor in the direction of the output shaft or the torque flow from the transmission back to the motor is limited.